Correction coefficient calculation unit, image conversion unit, color correction device, display device, correction coefficient calculation method, and program

ABSTRACT

A correction coefficient calculation unit includes: a reference image output unit that generates a reference image; a profile receiving unit that receives image information and printing information, the image information indicating a color characteristic related to an image to be displayed on a display unit, the printing information indicating a color characteristic related to a printing device; and a reference image division unit that creates printing characteristic data that associates the reference image with the reference image that has undergone color conversion based on the printing information and the image information.

TECHNICAL FIELD

The present invention relates to a correction coefficient calculationunit, an image conversion unit, a color correction device, a displaydevice, a correction coefficient calculation method, and a program.

BACKGROUND ART

In DTP (desktop publishing) companies which design printed materials,several personal computers (hereunder, referred to as PCs) used inworkflows, and display devices connected to each of the PCs are used insome cases.

When using several display devices in this way, there is a need to setthe several display devices with the printed material, which is thefinal deliverable, as a color reference. In this case, output results ofthe several display devices and a printing device are required to be thesame, and setting of a number of display devices needs to be doneeasily.

For this reason, it has been proposed to reproduce colors by means oftypically used color management, by generating a color conversion tablefor reproducing on the display device, the colors that will appear onthe target output device, and correcting the colors of an image to bedisplayed using the generated color correction information (for example,refer to Patent Document 1).

PRIOR ART DOCUMENTS Patent Documents

[Patent Document 1] Japanese Patent Publication No. 5322326

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

However, in the invention disclosed in Patent Document 1, while the sameoutput results can be achieved between a display device and a printingdevice for each display device, there is a problem in that settingcannot be easily performed for a number of display devices.

The present invention takes into consideration the above problem, withan object of providing a color correction device, a display device, acolor correction method, and a program that are capable of easilyadjusting several display devices to the output of a printing devicethat serves as a reference.

Means for Solving the Problem

In order to achieve the above object, a correction coefficientcalculation unit according to the present invention includes: areference image output unit that generates a reference image; a profilereceiving unit that receives image information and printing information,the image information indicating a color characteristic related to animage to be displayed on a display unit, the printing informationindicating a color characteristic related to a printing device; and areference image division unit that creates printing characteristic datathat associates the reference image with the reference image that hasundergone color conversion based on the printing information and theimage information.

In order to achieve the above object, an image conversion unit accordingto the present invention includes: a display correction data creationunit that creates display correction data based on display informationand image information, the display information indicating a colorcharacteristic related to a display unit, the image informationindicating a color characteristic related to an image to be displayed onthe display unit; a printing characteristic memory unit that receivesprinting characteristic data, the printing characteristic data beingcreated by associating a reference image with the reference image thathas undergone color conversion based on printing information and theimage information, the printing information indicating a colorcharacteristic related to a printing device; and an image correctionunit that creates color correction information based on the displaycorrection data and the printing characteristic data, the imagecorrection unit performing color correction on an input image signalbased on the created color correction information.

In order to achieve the above object, a color correction deviceaccording to the present invention includes a correction coefficientcalculation unit and an image conversion unit, the correctioncoefficient calculation unit including: a reference image output unitthat generates a reference image; a profile receiving unit that receivesimage information and printing information, the image informationindicating a color characteristic related to an image to be displayed ona display unit, the printing information indicating a colorcharacteristic related to a printing device; and a reference imagedivision unit that creates printing characteristic data that associatesthe reference image with the reference image that has undergone colorconversion based on the printing information and the image information,the image conversion unit including: a display correction data creationunit that creates display correction data based on display informationand image information, the display information indicating a colorcharacteristic related to the display unit, the image informationindicating a color characteristic related to the image to be displayedon the display unit; a printing characteristic memory unit that receivesprinting characteristic data, the printing characteristic data beingcreated by associating a reference image with the reference image thathas undergone color conversion based on printing information and theimage information, the printing information indicating a colorcharacteristic related to the printing device; and an image correctionunit that creates color correction information based on the displaycorrection data and the printing characteristic data, and that performscolor correction on an input image signal based on the created colorcorrection information.

In order to achieve the above object, a color correction deviceaccording to the present invention includes a setting unit and an imageconversion unit, the setting unit including: a data receiving unit thatreceives image information and printing characteristic data from anothercolor correction device, the printing characteristic data being createdby associating a reference image with the reference image that hasundergone color conversion based on printing information and the imageinformation, the printing information indicating a color characteristicrelated to a printing device, the image information indicating a colorcharacteristic related to an image to be displayed on a display unit,the printing characteristic data being created by said another colorcorrection device; and a display setting unit that outputs, to the imageconversion unit, the printing characteristic data and the imageinformation received by the data receiving unit, the image conversionunit including: a display correction data creation unit that createsdisplay correction data based on display information and the imageinformation, the display information indicating a color characteristicrelated to the display unit, the image information being received fromthe setting unit; a printing characteristic memory unit that receivesthe printing characteristic data from the setting unit; and an imagecorrection unit that creates color correction information based on thedisplay correction data and the printing characteristic data, the imagecorrection unit performing color correction on an input image signalbased on the created color correction information.

In order to achieve the above object, a display device according to thepresent invention includes: a display unit that displays an image; adisplay correction data creation unit that creates display correctiondata based on display information and image information, the displayinformation indicating a color characteristic related to the displayunit, the image information indicating a color characteristic related tothe image to be displayed on the display unit; a printing characteristicmemory unit that receives printing characteristic data, the printingcharacteristic data being created by associating a reference image withthe reference image that has undergone color conversion based onprinting information and the image information, the printing informationindicating a color characteristic related to a printing device; and animage correction unit that creates color correction information based onthe display correction data and the printing characteristic data, theimage correction unit performing color correction on an input imagesignal based on the created color correction information, the displayunit displaying an image based on the image signal that has undergonethe color correction.

In order to achieve the above object, a correction coefficientcalculation method according to the present invention includes: areference image output step of generating a reference image; a profilereceiving step of receiving image information and printing information,the image information indicating a color characteristic related to animage to be displayed on a display unit, the printing informationindicating a color characteristic related to a printing device; and areference image division step of creating printing characteristic datathat associates the reference image with the reference image that hasundergone color conversion based on the printing information and theimage information.

In order to achieve the above object, a program according to the presentinvention causes a computer to execute: a reference image output step ofgenerating a reference image; a profile receiving step of receivingimage information and printing information, the image informationindicating a color characteristic related to an image to be displayed ona display unit, the printing information indicating a colorcharacteristic related to a printing device; and a reference imagedivision step of creating printing characteristic data that associatesthe reference image with the reference image that has undergone colorconversion based on the printing information and the image information.

Effect of the Invention

According to the present invention, a plurality of display devices canbe easily adjusted to the output of a printing device that serves as areference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a display systemaccording to a present embodiment.

FIG. 2 is a block diagram of a schematic configuration of a colorcorrection device and a color conversion device according to the presentembodiment.

FIG. 3 is a diagram showing an example of a reference image in thepresent embodiment.

FIG. 4 is a diagram showing an example of a reference image in which thecolor space has been converted, in the present embodiment.

FIG. 5 is a flowchart of process steps performed by the color correctiondevice and the color conversion device according to the presentembodiment.

FIG. 6 is a block diagram of a schematic configuration of a colorcorrection device according to the present embodiment.

FIG. 7 is a flowchart of process steps performed by a setting unit andan image conversion unit according to the present embodiment.

FIG. 8 is a schematic configuration diagram of a display systemaccording to the present embodiment.

FIG. 9 is a block diagram of a schematic configuration of a PC includinga correction coefficient calculation unit and a color conversion device,and a display device including an image conversion unit, according tothe present embodiment.

FIG. 10 is a block diagram of a schematic configuration of a PCincluding a setting unit, and a display device including an imageconversion unit, according to the present embodiment.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereunder, embodiments of the present invention are described in detail,with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a display system 1according to a present embodiment.

As shown in FIG. 1, the display system 1 is configured by includingcolor correction devices 10-1 to 10-n (where n is an integer not lessthan 1), a color conversion device 20, and display units 40-1 to 40-n.In the following description, the color correction devices 10-1 to 10-nare referred to as color correction device 10 unless otherwisespecified, and the display units 40-1 to 40-n are referred to as displayunit 40 unless otherwise specified.

The display unit 40 is a liquid crystal panel, for example. The displayelement equipped in the display unit 40 may be a display element otherthan the liquid crystal type such as an organic electroluminescencedisplay element, an inorganic electroluminescence display element, aPALC (plasma address liquid crystal), a PDP (plasma display panel), andan FED (field emission display). Moreover, the display unit 40 includesa backlight and a backlight driving unit (not shown in the figure).

To the color correction device 10-1 there are connected a colorconversion device 20 and a display unit 40-1. The connection between thecolor correction device 10-1 and the color conversion device 20 may be awired connection or wireless connection. Based on various types ofinformation input, the color correction device 10-1 creates correctiondata (printing characteristic data and display correction data) forcorrecting an input video signal so as to achieve the same displaycharacteristic as that of a printed material. The color correctiondevice 10-1 uses the created printing characteristic data and displaycorrection data to correct the input video signal and display it on thedisplay unit 40-1. The color correction device 10-1 creates printingcharacteristic data, using image data in which the color space isconverted by the color conversion device 20. The various types ofinformation are rendering intent information, image profile information,and printing profile information.

To the color correction devices 10-2 to 10-n there are connected thedisplay units 40-2 to 40-n respectively. Each of the color correctiondevices 10-2 to 10-n receives an image profile and printingcharacteristic data created by the color correction device 10-1, andbased on the received printing characteristic data information and imageprofile, it creates correction data for correcting an input video signal(display correction data). Each of the color correction devices 10-2 to10-n uses each created display correction data to correct the inputvideo signal and display it on the display unit 40-1.

In FIG. 1, an example has been described in which the color correctiondevice 10 and the display unit 40 are separated. However, the colorcorrection device 10 and the display unit 40 may be integrated.

Here the various types of information used in the present embodiment aredescribed.

Rendering intent information is a piece of information that defines thetype of intention that color space conversion is to be performed for.For example, for a process in a case where a color reproduction regionbecomes narrow when performing conversion, an ICC profile has threecolor conversion tables namely perceptual, colorimetric, and saturationpriority prepared therein.

Image profile information is a profile that corresponds to an image tobe displayed on the display unit 40. There are various types of standardof image profile information such as sRGB, Adobe RGB, NTSC, and DCI.

Printing profile information (output profile information) is a profilethat corresponds to a printing device (not shown in the figure). Thereare various types of standard of printing profile information such asJapan Color, SWOP, and EuroPress.

Display profile information is a profile that corresponds to the colorcorrection device 10. Display profile information is a piece ofinformation that indicates a characteristic of the color correctiondevice 10 to be used for previewing, and it differs for each displayunit 40.

The profile information is data that defines a relationship betweendigital values and colors of the image, and the display unit 40, and theprinting device. The profile information includes a mutual relationshipbetween the RGB color space and the CMYK color space, a mutualrelationship between the RGB (or sRGB) color space and the CIE XYZ colorspace, and a mutual relationship between the CMYK color space and theCIELAB color space, for example. In the present embodiment there isdescribed a case of previewing a printed material in which an image ofthe sRGB standard is printed with the Japan Color standard.

FIG. 2 is a block diagram of a schematic configuration of the colorcorrection device 10 and the color conversion device 20 according to thepresent embodiment. As shown in FIG. 2, to the color correction device10 there are connected a color conversion device 20, a video outputdevice 30, and a display unit 40.

The video output device 30 outputs a video signal to the colorcorrection device 10. The video output device 30 is a PC (personalcomputer) or a mobile terminal, for example.

The color correction device 10 includes a correction coefficientcalculation unit 11 and an image conversion unit 12. Furthermore, thecorrection coefficient calculation unit 11 includes a reference imageoutput unit 111, a profile receiving unit 112, and a reference imagedivision unit 113.

The color correction device 10 transmits to the color conversion device20, a reference image and parameters used in color conversion, receivesthe converted reference image from the color conversion device 20, andcalculates color correction information from the reference image beforeand after the conversion. Moreover, the color correction device 10performs color correction on the image signal inputted from the videooutput device 30 such as a personal computer or a video device, based onthe calculated color correction information, and transmits thecolor-corrected image signal to the display unit 40. Here, the displayunit 40 is an LCD (liquid crystal display), a PJ (projector) or thelike, and it displays the image based on the image signal that hasundergone the color correction.

Moreover, the parameters used in the color conversion include renderingintent information, image profile information corresponding to thereference image, and printing profile information corresponding to theprinting device (output profile information).

The reference image output unit 111 creates for example, the referenceimage shown in FIG. 3, and outputs the created reference image to thecolor conversion device 20 and the reference image division unit 113.The reference image includes for example, colors of the total correctionpoints 9×9×9, which combine nine points in which the 256 scales (8 bit)of each of RGB (red, green, and blue) are extracted for every 32 scales.FIG. 3 is a diagram showing an example of a reference image in thepresent embodiment. As shown in FIG. 3, the reference image is an imagein which color chips of 9×9×9 points correction points are arranged. Thereference image is such that an image showing the color of (R, G,B)=(255, 255, 255) is arranged in the region A, and an image showing thecolor of (R, G, B)=(255, 255, 224) is arranged in the region B.Moreover, the reference image is such that an image showing the color of(R, G, B)=(255, 224, 224) is arranged in the region C, and an imageshowing the color of (R, G, B)=(224, 224, 224) is arranged in the regionD. A color chip is a piece of information showing colors, and includesvalues that indicate the respective levels of three colors, red, green,and blue (R, G, B). Instead of using a reference image that includescolor chips of several correction points, several reference imagesincluding only the color chip of a single correction point may be used.

The profile receiving unit 112 receives input of rendering intentinformation, image profile information that is selected by the user, andprinting profile information. The profile receiving unit 112 outputs tothe color conversion device 20, the rendering intent information, theimage profile information, and the printing profile information thathave been input. The profile receiving unit 112 outputs the input imageprofile information to the image conversion unit 12.

The reference image division unit 113 receives the reference image (FIG.4) that has undergone the color conversion from the color conversiondevice 20, and receives an input of the reference image (FIG. 3) fromthe reference image output unit 111. Moreover, the reference imagedivision unit 113 divides the region indicating the color included ineach of the reference images before and after the color spaceconversion, into 9×9×9 image regions, and respectively associates thedivided image regions for before and after the color conversion, tothereby calculate a correction coefficient (printing characteristicdata). The reference image division unit 113 outputs the calculatedprinting characteristic data to the image conversion unit 12. Theprinting characteristic data is of a 3D LUT (3 dimension look up table)configuration, in which the reference image is set to an input pointgroup and the image received from the color conversion device 20 is setto an output point group.

FIG. 4 is a diagram showing an example of the reference image that hasundergone color space conversion, in the present embodiment. In thereference image that has undergone the color space conversion, as withthe reference image (FIG. 3), there are arranged 9×9×9 image regionsthat have undergone the color conversion. As shown in FIG. 4, a regionshowing the color of (R, G, B)=(255, 255, 255) is arranged in the regionA′, an image showing the color of (R, G, B)=(255, 243, 211) is arrangedin the region B′, an image showing the color of (R, G, B)=(200, 210,223) is arranged in the region C′, and an image showing the color of (R,G, B)=(230, 225, 200) is arranged in the region D. Moreover, the colorof the region A of FIG. 3 corresponds to that of the region A′ of FIG. 4that has undergone color conversion in the color conversion device 20.Similarly, the color of the region B corresponds to the color of theregion B′, the color of the region C corresponds to that of the regionC′, and the color of the region D corresponds to the color of the regionD′.

The color conversion device 20 includes a color conversion engine 21 anda color conversion engine 22.

Based on the rendering intent information output by the profilereceiving unit 112, the color conversion engine 21 converts, forexample, the reference image of the sRGB color space output by thereference image division unit 113 into, for example, an image of theCMYK color space, using the image profile and printing profile. Forexample, the color conversion engine 21 converts an input referenceimage from the sRGB standard color space to the Japan Color standardcolor space. The color conversion engine 21 outputs the reference image,which has been color-converted into the image of the CMYK color space,to the color conversion engine 22.

The color conversion engine 22 converts the reference image of the CMYKcolor space output by the reference image division unit 113 into animage of the RGB color space, using the image profile and printingprofile output by the profile receiving unit 112. The color conversionengine 22 outputs the reference image, which has been color-convertedinto the image of the RGB color space, to the reference image divisionunit 113 of the color correction device 10. For example, the colorconversion engine 22 converts an input reference image from the JapanColor standard color space to the sRGB standard color space. The colorconversion engines 21 and 22 are applications or software included inoperating systems that are commonly and widely used, such as ACE ofAdobe Systems Incorporated, ICM 2.0 or WCS of Microsoft Corporation, andColor Sync (registered trademark) of Apple Inc.

The image conversion unit 12 includes a print characteristic memory unit121, an image profile memory unit 122, a display profile memory unit123, a display correction data creation unit 124, and an imagecorrection unit 125.

The print characteristic memory unit 121 stores printing characteristicdata output by the reference image division unit 113.

The image profile memory unit 122 stores image profile informationoutput from the profile receiving unit 112.

The display profile memory unit 123 stores a display profile including adisplay characteristic, color gamut, white spot, and gammacharacteristic of the display unit 40 which is connected to the colorcorrection device 10. The display profile memory unit 123 may storedisplay characteristic information. In this case, the image conversionunit 12 may use the display characteristic stored in the display profilememory unit 123 to thereby create a display profile.

The display correction data creation unit 124 reads an image profilestored in the image profile memory unit 122, and reads a display profilestored in the display profile memory unit 123. The display correctiondata creation unit 124 creates display correction data by means of acommonly known method, based on the image profile that defines therelationship of conversion from the RGB color space to the CIE XYZ colorspace, and the display profile that defines the relationship ofconversion from the CIE XYZ color space to the RGB color space. Withthis display correction data, conversion to the different RGB colorspace becomes possible. The display correction data creation unit 124outputs the created display correction data to the image correction unit125.

The image correction unit 125 includes a 3D LUT (3 dimension look uptable) 1251. The image correction unit 125 reads the printingcharacteristic data stored in the print characteristic memory unit 121,and receives the display correction data output by the displaycorrection data creation unit 124. The image correction unit 125 createsa correction coefficient using the printing characteristic data and thedisplay correction data, and sets the created correction coefficient tothe 3D LUT 1251. The image correction unit 125 corrects the input videosignal based on the 3D LUT 1251, and outputs the corrected video signalto the display unit 40. The image correction unit 125 may include agamma correction unit (1D LUT×3) and a backlight driving unit.

Next, processes performed by the correction coefficient calculation unit11, the color correction device 10, and the color conversion device 20are described. FIG. 5 is a flowchart of process steps performed by thecolor correction device 10 and the color conversion device 20 accordingto the present embodiment.

-   (Step S1) The profile receiving unit 112 receives an image profile    (for example, sRGB standard data).-   (Step S2) The profile receiving unit 112 receives a printing profile    (for example, Japan Color standard data).-   (Step S3) The reference image output unit 111 creates a reference    image. The reference image to be created is an image that represents    correction points of the color correction device 10.-   (Step S4) The reference image output unit 111 outputs the created    reference image to the color conversion engine 21 of the color    conversion device 20.-   (Step S5) Based on the rendering intent information output by the    profile receiving unit 112, the color conversion engine 21 converts,    for example, the reference image of the RGB color space output by    the reference image division unit 113 into, for example, an image of    the CMYK color space, using the image profile and printing profile.-   (Step S6) The color conversion engine 22 converts the reference    image of the CMYK color space output from the reference image    division unit 113 into an image of the RGB color space, using the    image profile and printing profile output from the profile receiving    unit 112. The color conversion engine 22 outputs the reference    image, which has been color-converted into the image of the RGB    color space, to the reference image division unit 113 of the color    correction device 10.-   (Step S7) The reference image division unit 113 receives the    reference image that has undergone the color conversion from the    color conversion device 20.-   (Step S8) The reference image division unit 113 divides the region    indicating the color included in each of the reference images before    and after the color space conversion, into 9 ×9×9 image regions, and    respectively associates the divided image regions for before and    after the color conversion, to thereby create printing    characteristic data, which is a correction coefficient.-   (Step S9) The reference image division unit 113 outputs the created    printing characteristic data to the image conversion unit 12.-   (Step S10) The image conversion unit 12 uses the display    characteristic stored in the display profile memory unit 123 to    thereby create a display profile.-   (Step S11) The display correction data creation unit 124 creates    display correction data based on the image profile read from the    image profile memory unit 122 and the display profile read from the    display profile memory unit 123.-   (Step S12) The image correction unit 125 reads the printing    characteristic data stored in the print characteristic memory unit    121, and receives the display correction data output by the display    correction data creation unit 124. Next, the image correction unit    125 creates a correction coefficient, using the printing    characteristic data and the display correction data, and sets the    created correction coefficient to the 3D LUT 1251.-   (Step S13) The image correction unit 125 corrects the input video    signal based on the 3D LUT 1251, and outputs the corrected video    signal to the display unit 40.

This completes the processes performed by the color correction device 10and the color conversion device 20.

The processes of steps S1 through S13 complete image quality setting ofthe color correction device 10 to suit the printed material. Throughthese processes, the color correction device 10-1 stores the createdprinting characteristic data and display correction data.

The example above has been described as an example where the colorcorrection device 10-1 includes a correction coefficient calculationunit 11 and an image conversion unit 12, and the color correctiondevices 10-2 to 10-n include a setting unit 13 and an image conversionunit 12. All of the color correction devices 10 may include a correctioncoefficient calculation unit 11, a setting unit 13, and an imageconversion unit 12.

As described above, the correction coefficient calculation unit of thepresent embodiment includes: a reference image output unit thatgenerates a reference image; a profile receiving unit that receivesimage information and printing information, the image informationindicating a color characteristic related to an image to be displayed ona display unit, the printing information indicating a colorcharacteristic related to a printing device; and a reference imagedivision unit that creates printing characteristic data that associatesthe reference image with the reference image that has undergone colorconversion based on the printing information and the image information.

Moreover, the image conversion unit of the present embodiment includes:a display correction data creation unit that creates display correctiondata based on display information and image information, the displayinformation indicating a color characteristic related to a display unit,the image information indicating a color characteristic related to animage to be displayed on the display unit; a printing characteristicmemory unit that receives printing characteristic data, the printingcharacteristic data being created by associating a reference image withthe reference image that has undergone color conversion based onprinting information and the image information, the printing informationindicating a color characteristic related to a printing device; and animage correction unit that creates color correction information based onthe display correction data and the printing characteristic data, theimage correction unit performing color correction on an input imagesignal based on the created color correction information.

Furthermore, the color correction device of the present embodimentincludes a correction coefficient calculation unit and an imageconversion unit, the correction coefficient calculation unit including:a reference image output unit that generates a reference image; aprofile receiving unit that receives image information and printinginformation, the image information indicating a color characteristicrelated to an image to be displayed on a display unit, the printinginformation indicating a color characteristic related to a printingdevice; and a reference image division unit that creates printingcharacteristic data that associates the reference image with thereference image that has undergone color conversion based on theprinting information and the image information, the image conversionunit including: a display correction data creation unit that createsdisplay correction data based on display information and imageinformation, the display information indicating a color characteristicrelated to the display unit, the image information indicating a colorcharacteristic related to the image to be displayed on the display unit;a printing characteristic memory unit that receives printingcharacteristic data, the printing characteristic data being created byassociating a reference image with the reference image that hasundergone color conversion based on printing information and the imageinformation, the printing information indicating a color characteristicrelated to the printing device; and an image correction unit thatcreates color correction information based on the display correctiondata and the printing characteristic data, and that performs colorcorrection on an input image signal based on the created colorcorrection information.

With this configuration, the correction coefficient calculation unit ofthe present embodiment can create printing characteristic data.Moreover, with this configuration, the image conversion unit of thepresent embodiment can create display correction data.

Furthermore, since the color correction device of the present embodimentcan create printing attribute data and display correction data, it ispossible to perform color correction on an input image signal to suitthe printing device.

Next is described image quality setting with respect to the colorcorrection devices 10-2 to 10-n to suit a printed material.

FIG. 6 is a block diagram of a schematic configuration of a colorcorrection device 10A according to the present embodiment. As shown inFIG. 6, to the color correction device 10A there are connected a videooutput device 30 and a display unit 40. Functional units having the samefunctions as those of the color correction device 10 are denoted by thesame reference symbols, and descriptions thereof are omitted.

The color correction device 10A includes a setting unit 13 and an imageconversion unit 12. Furthermore, the setting unit 13 includes a datareceiving unit 131 and a display setting unit 132. Moreover, as with thecolor correction device 10, the image conversion unit 12 includes aprint characteristic memory unit 121, an image profile memory unit 122,a display profile memory unit 123, a display correction data creationunit 124, and an image correction unit 125.

The data receiving unit 131 receives image profile information andprinting characteristic data information from the color correctiondevice 10-1, and outputs the received image profile information and theprinting characteristic data information to the display setting unit132. The data receiving unit 131 may transmit and receive image profileinformation and printing characteristic data information by means ofwireless communication or wired communication, or may receive imageprofile information and printing characteristic data information via arecording medium such as a USB (universal serial bus).

The display setting unit 132 stores the printing characteristic datainformation output by the data receiving unit 131 in the printcharacteristic memory unit 121 of the image conversion unit 12. Thedisplay setting unit 132 stores the image profile information output bythe data receiving unit 131 in the image profile memory unit 122.

Next, processes performed by the setting unit 13 and the imageconversion unit 12 are described. FIG. 7 is a flowchart of process stepsperformed by the setting unit 13 and the image conversion unit 12according to the present embodiment.

-   (Step S101) The data receiving unit 131 receives image profile    information from the color correction device 10-1.-   (Step S102) The data receiving unit 131 receives printing    characteristic data information from the color correction device    10-1.-   (Step S103) The display setting unit 132 stores the printing    characteristic data information output by the data receiving unit    131 in the print characteristic memory unit 121 of the image    conversion unit 12. Next, the display setting unit 132 stores the    image profile information output by the data receiving unit 131 in    the image profile memory unit 122.-   (Step S104) The image conversion unit 12 creates a display profile    based on the characteristic of the display unit, and stores the    created display profile in the display profile memory unit 123. The    display profile may be preliminarily stored in the display profile    memory unit 123.-   (Step S105) The display correction data creation unit 124 creates    display correction data based on the printing characteristic data    read from the print characteristic memory unit 121 and the display    profile read from the display profile memory unit 123. The display    correction data created by the display correction data creation unit    124 in this step S105, in the case where the color correction device    10-2 performs the process, for example, is data that suit the    display unit 40-2 connected to the color correction device 10-2.    Therefore, it may differ from the display correction data created by    the color correction device 10-1 in step S11 in some cases.-   (Step S106) The image correction unit 125 creates a correction    coefficient, using the printing characteristic data and the display    correction data, and sets the created correction coefficient to the    3D LUT 1251.-   (Step S107) The image correction unit 125 corrects the input video    signal based on the 3D LUT 1251, and outputs the corrected video    signal to the display unit 40.

This completes the processes performed by the setting unit 131 and theimage conversion unit 12.

The processes of step S101 through step S107 complete the image qualitysetting of the color correction device 10-n to suit the printedmaterial. For example, the administrator of the color correction devices10-1 to 10-n can perform image quality setting on n units of colorcorrection devices 10 to suit the printed material, by means of theprocesses of step S1 through step S13 and step S101 through step S107described above. As a result, according to the present embodiment, forexample, in the case where n=100, 100 units of color correction devices10 can be all adjusted to achieve the same image display state.

As described above, the color correction device of the presentembodiment includes a setting unit and an image conversion unit, thesetting unit including: a data receiving unit that receives imageinformation and printing characteristic data from another colorcorrection device, the printing characteristic data being created byassociating a reference image with the reference image that hasundergone color conversion based on printing information and the imageinformation, the printing information indicating a color characteristicrelated to a printing device, the image information indicating a colorcharacteristic related to an image to be displayed on a display unit,the printing characteristic data being created by said another colorcorrection device; and a display setting unit that outputs, to the imageconversion unit, the printing characteristic data and the imageinformation received by the data receiving unit, the image conversionunit including: a display correction data creation unit that createsdisplay correction data based on display information and the imageinformation, the display information indicating a color characteristicrelated to the display unit, the image information being received fromthe setting unit; a printing characteristic memory unit that receivesthe printing characteristic data from the setting unit; and an imagecorrection unit that creates color correction information based on thedisplay correction data and the printing characteristic data, the imagecorrection unit performing color correction on an input image signalbased on the created color correction information.

With this configuration, according to the present embodiment, even ifthere are a plurality of color correction devices 10, there may be asingle color conversion device 20 including color conversion engines 21and 22. Other color correction devices receive printing characteristicdata that is created by the color conversion device 20 including thecolor conversion engines 21 and 22. As a result, according to thepresent embodiment, only a single license is needed when realizing acolor conversion engine by means of software, and therefore, the cost ofthe display system 1 can be reduced significantly.

The processes described above may be performed by each color correctiondevice 10 in a synchronized manner.

FIG. 8 is a schematic configuration diagram of a display system 1Aaccording to the present embodiment. As shown in FIG. 8, the colorcorrection device 10-1 includes a transmission unit 14. In FIG. 8, anexample is shown where the color conversion device 20 is connected tothe color correction device 10-1. However, any one of the colorcorrection devices 10-1 through 10-n may be connected to the colorconversion device 20. The color correction devices 10-1 to 10-n areconnected to each other via a network 50. The network 50 is either awired network or a wireless network.

The transmission unit 14 transmits the image profile informationreceived by the data receiving unit 131 and the printing characteristicdata created by the correction coefficient calculation unit 11, to theother color correction devices 10-2 to 10-n via the network 50.

Each of the color correction devices 10-2 to 10-n may acquire imageprofile information via the network 50.

For example, when the power supply of the preliminarily determined colorcorrection device 10-1 among 100 units of the color correction devices10 is brought to the ON state, the color correction device 10-1 acquiresrendering intent information, image profile information, and printingprofile information via the network 50. The color correction device 10-1creates printing characteristic data, display correction data, and acorrection coefficient. The color correction device 10-1 then transmitsthe created printing characteristic data and the acquired image profileinformation, to the color correction devices 10-2 to 10-n via thenetwork 50. Then, each of the color correction devices 10-2 to 10-ncreates display correction data and a correction coefficient based on,the received printing characteristic data and image profile information,and also the characteristics of the display units 40-2 to 40-n connectedto the respective color correction devices 10.

Moreover, in the present embodiment, there has been described an examplewhere the color correction device 10 acquires rendering intentinformation, image profile information, and printing profile informationat the time of start-up for example. However, it is not limited to this.For example, in the case where several printing devices are connected toseveral color correction devices 10, the color correction device 10needs to acquire rendering intent information, image profileinformation, and printing profile information for each printing device.In this case, for example, when using a different printing device, theadministrator of the display system 1B may transmit, from the terminalthat the administrator uses, rendering intent information, image profileinformation, and printing profile information to the color correctiondevices 10 via a network. Then, the preliminarily determined colorcorrection device 10 may execute the processes of the steps S1 throughS13 described above at the timing of having received these pieces ofinformation.

As described above, according to the present embodiment, a settingoperation that uses a number of files does not have to be repeatedlyperformed on all of the display devices (color correction devices 10 anddisplay units 40). In this type of cumbersome operation, carelessmistakes such as using an incorrect parameter is likely to occur. On theother hand, according to the present embodiment, there is no need forperforming this type of cumbersome operation, and therefore, carelessmistakes such as using an incorrect parameter can be avoided.

Furthermore, according to the present embodiment, the color conversionengine does not have to be installed on several PCs that are connectedto the display devices (color correction devices 10 and display units40), but only needs to be installed on a single PC. As a result,according to the present embodiment, since the license cost is requiredonly for a single PC, the cost of the display system 1 (or 1B) can bereduced significantly.

Moreover, according to the present embodiment, after having transmittedsingle correction data to several display devices (color correctiondevices 10 and display units 40), the respective display devices (colorcorrection devices 10 and display units 40) further correct the receivedcorrection data so as to suit the respective display units 40. Thereforethe display characteristics of the several display devices can bematched.

Furthermore, in the present embodiment, there has been described anexample where the color correction device 10 performs correction that iscreated with use of printing characteristic data. However, it is notlimited to this. Since the printing characteristic data and the displaycorrection data are separately stored in the color correction device 10,the user may use the color correction device 10, while using the displaycorrection data, by switching whether or not to reflect the printingcharacteristic data according to the intended use. As a result,according to the present embodiment, changes in color associated withprinting (difference between the original display characteristic andprinting characteristic) can be confirmed by instantaneously switchingthe display characteristic of the display.

Moreover, in the present embodiment, there has been described an examplewhere the color correction device 10 stores one each of image profile,printing characteristic data, and display correction data. However, itis not limited to this. The color correction device 10 may store severalsets of image profile, printing characteristic data, and displaycorrection data. The user may switch and use the stored settingsaccording to the intended use.

In the present embodiment, there has been described an example where asingle display unit 40 is connected to the color correction device 10(or 10B) as shown in FIG. 1, FIG. 2, FIG. 6, and FIG. 8. However, theremay be several display units 40. In the case where several display units40 are connected to the color correction device 10, the image conversionunit 12 of the color correction device 10 may create display profileinformation for each display unit 40, and create display correction datafor each display unit 40, using the created several display profiles.Then the color correction device 10 may use the created displaycorrection data for each display unit 40, and correct the input imagesignal and display it on each display unit 40.

Furthermore, for example, in the case where two display units 40 areconnected to the color correction device 10, as described above, aselection as to whether or not to reflect printing characteristic datafor each display unit 40 may be allowed. For example, an image thatreflects printing characteristic data may be displayed on one of thedisplay units 40, and an image that does not reflect printingcharacteristic data may be displayed on the other display unit 40.

In the above embodiment, the reference image output unit 111 is of aconfiguration that outputs a reference image in which the 256 scales ofeach of RGB are extracted for every 32 scales. However, it is notlimited to this, and correction points may be changed according to theimage signal output by the video output device 30. For example, the usermay select any one of color evaluation patterns such as ISO12646,GRACoL206, and FOGRA39, and a reference image may be generated based onthe selected color evaluation pattern. As a result, as for conversionerrors in the color conversion device 20, an image characteristicaccording to the picture and intended use of an image signal can bereflected on correction points, and errors in color conversion can besuppressed. An image characteristic, for example, in an image signalbased on a movie film, is that dark pictures mainly with black colorsare predominant.

Moreover, colors that are highly visible to the human eye such as skincolors may be prioritized, that is to say, many correction points may bearranged for colors that are close to skin colors, to generate areference image. As a result, the level of reproduction in a printpreview can be improved for printed materials, which often havephotographs of people.

Moreover, the reference image output unit 111 may generate a referenceimage that includes colors of the total correction points 9×9×9, whichcombine nine points in which the 256 scales (8 bit) of each of RGB areextracted for every 32 scales, and a reference image in which only graycolors that change from black to white are taken as correction points.The user may then select from the reference images when performing printpreview of a black-and-white printed material containing gray colors,and when performing print preview of colored printed material. As aresult, it is possible to perform print preview according to the printedmaterial, and the level of reproduction can be improved.

In the embodiment described above, the color conversion device 20converts a reference image from an sRGB standard RGB value to a JapanColor standard CMYK value, and from a Japan Color standard CMYK value toan RGB value of the color space of the display device 4, through twocolor conversions. However, it is not limited to this. The colorconversion device 20 may convert color information that is dependent onan input/output device of RGB or CMYK into PCS information of a colorspace that is independent of an input/output device, and may convertthis PCS information into color information that is dependent on theinput/output device. Here, the PCS standard shows a profile connectioncolor space, and shows a color space that is independent of a displaydevice such as Lab and XYZ, and an input/output device such as aprinting device.

In the embodiment described above, the description has been made using areference image that contains 9×9×9 color chips, which are correctionpoints. However, it is not limited to this, and the number of correctionpoints may be changed according to the memory capacity of the 3D LUT1251.

Moreover, in the embodiment described above, there has been described acase where the color of the printed material output by the printingdevice is reproduced on the display unit 40. However, it is not limitedto this, and the color of an output device other than a printing devicethat outputs an image may be reproduced on the display unit 40. Thecolor of an image to be displayed by another display device other thanthe display unit 40 such as a projector, for example, may be reproducedon the display unit 40 (LCD display). In this case, instead of usingprinting profile information, profile information that corresponds tothe output device may be used.

Furthermore, in the embodiment described above, the display profilememory unit 123 may use a standard value such as “2.2” as apreliminarily stored gamma characteristic. In this case, the displayprofile information stored in the display profile memory unit 123includes a standard gamma characteristic represented by a standardvalue, or a gamma correction value for adjusting the display unit 40 tothe standard gamma characteristic.

Moreover, the 3D LUT 1251 may calculate an additional correction valuebased on color vision abnormality or a different color visioncharacteristic such as a CIE1964X10Y10Z10 colorimetric system, and mayperform color correction on the color of each pixel of the input imagesignal.

The example above has been described as an example where one colorcorrection device 10 includes a correction coefficient calculation unit11 and an image conversion unit 12, and another color correction device10 includes a setting unit 13 and an image conversion unit 12. However,it is not limited to this. The PC may include a correction coefficientcalculation unit 11 or a setting unit 13, and the display device mayinclude an image conversion unit 12.

FIG. 9 is a block diagram of a schematic configuration of a PC 301including a correction coefficient calculation unit 11 and a colorconversion device 20, and a display device 302 including an imageconversion unit 12, according to the present embodiment.

As shown in FIG. 9, the display device 302 is connected to the PC 301.Moreover, the PC 301 includes a correction coefficient calculation unit11, a color conversion device 20, and a video output unit 3011.Furthermore, the display device 302 includes an image conversion unit 12and a display unit 40. Each configuration of the correction coefficientcalculation unit 11, the color conversion device 20, and the imageconversion unit 12 is similar to that of each unit of the colorcorrection device 10 (FIG. 10).

The PC 301 and the display device 302 are connected via a cable that iscapable of performing information exchange. The cable is a USB cable forexample. Alternatively, information exchange may be performed via thevideo cable that connects the PC 301 and the display device 302.

The correction coefficient calculation unit 11 and the color conversiondevice 20 of the PC 301 create printing characteristic data, using theacquired rendering intent information, the image profile information,the printing characteristic information, and the created referenceimage. The PC 301 acquires the rendering intent information, the imageprofile information, and the printing profile information via a networkor a recording medium that is connected to a USB terminal for example.The correction coefficient calculation unit 11 outputs the createdprinting characteristic data and the acquired image profile informationto the display device 302. Moreover, the PC 301 outputs the video signalcreated by the PC 301, from the video output unit 3011 to the displaydevice 302.

Furthermore, the PC 301 outputs the created printing characteristic datato another PC via a network.

The image conversion unit 12 of the display device 302 creates displaycorrection data that suits the display unit 40 of the display device 312itself, using the image profile information output from the PC 301 andthe display profile information created by the display device itself.The image conversion unit 12 creates a correction coefficient using thereceived printing characteristic information and the created displaycorrection data, and sets the created correction coefficient to the 3DLUT 1251. The image conversion unit 12 corrects the video signal inputfrom the PC 301 based on the 3D LUT 1251, and outputs the correctedvideo signal to the display unit 40.

FIG. 10 is a block diagram of a schematic configuration of a PC 301including a setting unit 13, and a display device 302 including an imageconversion unit 12, according to the present embodiment.

As shown in FIG. 10, the display device 312 is connected to the PC 311.Moreover, the PC 311 to 311 includes a setting unit 13 and a videooutput unit 3101. As with the display device 302, the display device 312includes an image conversion unit 12 and a display unit 40.

The setting unit 13 of the PC 311 receives image profile information,and printing characteristic data information output by the PC 301, via anetwork for example. The setting unit 13 outputs the received printingcharacteristic data information to the display device 312. Moreover, thesetting unit 13 outputs the received image profile information to thedisplay device 312. Furthermore, the PC 311 outputs the video signalcreated by the PC 311, from the video output unit 3101 to the displaydevice 312.

As with the image conversion unit 12 of the display device 302, theimage conversion unit 12 of the display device 312 creates displaycorrection data that suits the display unit 40 of the display device 312itself. The image conversion unit 12 creates a correction coefficientusing the received printing characteristic information and the createddisplay correction data, and sets the created correction coefficient tothe 3D LUT 1251. The image conversion unit 12 corrects the video signalinput from the PC 311 based on the 3D LUT 1251, and outputs thecorrected video signal to the display unit 40.

In an environment where there are several combinations of a PC and adisplay device, the number of PCs 301 shown in FIG. 9 that includes acorrection coefficient calculation unit 11 and a color conversion device20 may be one. Another PC may be the PC 311 shown in FIG. 10 thatincludes a setting unit 13.

The PC 311 other than the PC 301 receives image profile information, andprinting characteristic data information output by the PC 301, via anetwork, and outputs the received image profile information and printingcharacteristic data information to the connected display device 312. Theimage conversion unit 12 of each display device 312 connected to PC 311corrects the video signal input from the PC 311 based on the 3D LUT1251, and outputs the corrected video signal to the display unit 40.

In this manner, according to the present embodiment, by simply havingonly the PC 301 including a color conversion device 20, image qualitysetting that suits the printed material can be performed on the displaydevice 302 and several display devices 312.

A program for realizing the functions of the color correction device 10of FIG. 2, the color correction device 10A of FIG. 6, the correctioncoefficient calculation unit 11 and the color conversion device 20 ofFIG. 9, and the image conversion unit 12 of FIG. 10 may be recorded on acomputer-readable recording medium, and the program recorded on thisrecording medium may be read and executed on a computer system tothereby perform the process of each unit. The “computer system” hereincludes an OS and hardware such as peripheral devices.

Moreover, the “computer system” includes, in the case where a WWW systemis used, a homepage provision environment (or display environment).

Furthermore, the “computer-readable recording medium” refers to aportable medium such as a flexible disk, magnetic optical disk, ROM(read only memory), and CD-ROM, a USB memory that is connected via a USB(universal serial bus) I/F (interface), or a memory device such as abuilt-in hard disk in a computer system. Furthermore, the“computer-readable recording medium” includes one that retains a programfor a certain period of time, such as a volatile memory inside acomputer system serving as a server or client. Moreover, the aboveprogram may be one that realizes a part of the functions describedabove, or may be one that realizes the functions described above incombination with a program that is already recorded on the computersystem.

REFERENCE SYMBOLS

-   1, 1B Display system-   10, 10A, 10B-1, 10-1 to 10-n Color correction device-   11 Correction coefficient calculation unit-   12 Image conversion unit-   14 Transmission unit-   20 Color conversion device-   21, 22 Color conversion engine-   30 Video output device-   40, 40-1 to 40-n Display unit-   50 Network-   111 Reference image output unit-   112 Profile receiving unit-   113 Reference image division unit-   121 Print characteristic memory unit-   122 Image profile memory unit-   123 Display profile memory unit-   124 Display correction data creation unit-   125 Image correction unit-   1251 3D LUT-   131 Data receiving unit-   132 Display setting unit-   301, 311 PC-   302, 312 Display device-   3011, 3101 Video output unit

The invention claimed is:
 1. A correction coefficient calculation devicecomprising: a computer executing computer instructions and configured toprovide: a reference image output unit that generates a reference image;a profile receiving unit that receives image information and printinginformation, the image information indicating a color characteristicrelated to an image to be displayed on a display unit, the printinginformation indicating a color characteristic related to a printingdevice; and a reference image division unit that creates printingcharacteristic data that associates the reference image with thereference image that has undergone color conversion based on theprinting information and the image information, wherein the referenceimage that has undergone color conversion is obtained by outputting thereference image, the printing information and the image information to acolor conversion device, and performing, by the color conversion device,color conversion on the reference image, the color conversion devicebeing separated from the correction coefficient calculation device. 2.The correction coefficient calculation device according to claim 1,wherein the image information includes image profile informationindicating a color characteristic corresponding to the image to bedisplayed on the display unit, and the printing information includesprint profile information and rendering intent, the print profileinformation indicating a color characteristic corresponding to theprinting device, the rendering intent indicating a method of color spaceconversion in the color conversion.
 3. The correction coefficientcalculation device according to claim 1, wherein the printingcharacteristic data includes a three dimension look up tableconfiguration in which the reference image is set to an input pointgroup and the reference image that has undergone color conversion is setto an output point group.
 4. The correction coefficient calculationdevice according to claim 1, wherein the color conversion deviceconverts the reference image into a first image of a CMYK color space,and further converts the first image into a second image of an RGB colorspace, and the color conversion device outputs, to the correctioncoefficient calculation device, the second image as the reference imagethat has undergone color conversion.
 5. A display method comprising:displaying an image on a display device; creating display correctiondata based on display information and image information, the displayinformation indicating a color characteristic related to the displaydevice, the image information indicating a color characteristic relatedto the image to be displayed on the display device; receiving printingcharacteristic data, the printing characteristic data being created byassociating a reference image with the reference image that hasundergone color conversion based on printing information and the imageinformation, the printing information indicating a color characteristicrelated to a printing device; creating color correction informationbased on the display correction data and the printing characteristicdata; performing color correction on an input image signal based on thecreated color correction information; and displaying, on the displaydevice, an image based on the image signal that has undergone the colorcorrection, wherein the reference image that has undergone colorconversion is obtained by outputting the reference image, the printinginformation and the image information from a correction coefficientcalculation unit to a color conversion device, and performing, by thecolor conversion device, color conversion on the reference image, thecolor conversion device being separated from the correction coefficientcalculation unit.
 6. The display method according to claim 5, whereinthe printing characteristic data includes a three dimension look uptable configuration in which the reference image is set to an inputpoint group and the reference image that has undergone color conversionis set to an output point group.
 7. The display method according toclaim 5, wherein the color conversion device converts the referenceimage into a first image of a CMYK color space, and further converts thefirst image into a second image of an RGB color space, and the colorconversion device outputs, to the correction coefficient calculationunit, the second image as the reference image that has undergone colorconversion.
 8. The display method according to claim 5 comprisinginstructions stored and executed on a computer.
 9. A correctioncoefficient calculation method comprising: generating a reference image;receiving image information and printing information, the imageinformation indicating a color characteristic related to an image to bedisplayed on a display device, the printing information indicating acolor characteristic related to a printing device; and creating printingcharacteristic data that associates the reference image with thereference image that has undergone color conversion based on theprinting information and the image information, wherein the referenceimage that has undergone color conversion is obtained by outputting thereference image, the printing information and the image information froma correction coefficient calculation unit to a color conversion device,and performing, by the color conversion device, color conversion on thereference image, the color conversion device being separated from thecorrection coefficient calculation unit.
 10. The correction coefficientcalculation method according to claim 9, wherein the printingcharacteristic data includes a three dimension look up tableconfiguration in which the reference image is set to an input pointgroup and the reference image that has undergone color conversion is setto an output point group.
 11. The correction coefficient calculationmethod according to claim 9, wherein the color conversion deviceconverts the reference image into a first image of a CMYK color space,and further converts the first image into a second image of an RGB colorspace, and the color conversion device outputs, to the correctioncoefficient calculation unit, the second image as the reference imagethat has undergone color conversion.
 12. The correction coefficientcalculation method according to claim 9 comprising instructions storedand executed on a computer.